积分时滞对象的一种新型复合控制策略

Composite Control Strategy for Process of Integrator Plus Time Delay

针对Smith预估器控制积分时滞对象时的鲁棒稳定性不强,且常值负荷扰动导致输出静差等问题,提出了一种负荷扰动补偿-预测比例积分复合控制策略.基于期望的互补灵敏度函数,反推出一个预测比例积分控制器用于稳定被控对象,并保证设定值扰动过程中的动态品质,同时设计了一个纯比例作用的负荷扰动补偿器,以消除负荷扰动对被控输出的影响.该控制策略有两个工程物理意义明确的可调参数,且参数的整定过程相对独立.仿真结果表明,在模型失配和负荷扰动存在的情况下,该系统仍可保持稳定的被控输出和光滑的控制作用,有较好的鲁棒稳定性和良好的动态调节品质.

Focusing on the poor robust stability and the static output error from the constant load disturbance when Smith predictor controls the process of integrator plus time delay, a composite control strategy is proposed, which consists of a predictive proportional integral （PPI） controller and a load disturbance compensator （LDC）. Based on an expected complementary sensitivity function, the PPI is directly deduced to stabilize the process and to ensure a satisfied performance of the servo response. The purely proportional LDC is designed to eliminate the effect of the load disturbance on the controlled output. The strategy has only two tuning parameters with definite engineering meanings, and the tuning procedures of the two parameters are relatively independ- ent. The simulations show that a stabilized output and a smooth control can still be hold even under the model mismatches and the load disturbance, which demonstrates good robust stability and dynamic regulating performance.